Chris Murphy, a Democrat who represents relatives of the Sandy Hook massacre, said political parties don’t just disagree on guns – ‘we are on different planets’

Policy arguments about gun control will not change the votes of the “neo-anarchist” Republican party, a Democratic senator said on Friday.

Speaking at a New York University Law School conference on the second amendment, Connecticut senator Chris Murphy argued that the stalemate over guns will only end when conservatives find a new way of proving their anti-government credentials to voters.

“Democrats and Republicans – we aren’t just having different conversations about guns, we are on different planets,” Murphy said.

Murphy said he was shocked when Congress failed to pass moderate gun control legislation after the 2012 school shooting at Sandy Hook elementary school in his state, even though polls show that “80% to 90% of Americans will tell you they wanted expanded background checks for people trying to buy guns”.

“Democracy is not supposed to allow for that to happen,” he said.

Murphy said that having been voted into office the month before the shooting, he had gone to Newtown and was with the family members of victims when they were told that 20 first-graders had been shot to death. Six adults also died.

Nearly four years later, Murphy said, Congress is still at an “irreconcilable impasse” when it comes to new gun laws.

“We can’t even have a debate on the judiciary committee, or a hearing on the subject,” he said. “We can’t even begin a legislative conversation about that in Washington.”

Murphy, who supports Hillary Clinton for president, has repeatedly criticized Bernie Sanders for his record on guns. Murphy slammed his fellow senator this week for his lack of support for a lawsuit by Sandy Hook families against the manufacturer, distributor and dealer of the military-style rifle that was used to kill their children.

In a speech to an audience of scholars and gun-policy experts, Murphy said that for Democrats, the gun debate is mainly focused on the “mechanics” of which policies will lead to more gun deaths and which policies will lead to fewer gun deaths.

“We are down in the weeds,” he said.

Republicans, he said, use their support of gun rights as a cornerstone in their strategy to win elections by launching “an all-out, no-holds-barred assault on government”.

“The Republicans in some way, shape or form have become a neo-anarchist party, in that they don’t accept that there is much legitimacy at all to the existence of public functions,” he said.

“The second amendment has become sacred because it’s the best way for them to express how furious they are at government. They are willing to defend the right of individuals to take up arms against it. There’s no way to get farther right on anti-government rhetoric than that.”

As American household firearm ownership shrinks, he said, the gun industry also relies on anti-government rhetoric about “black helicopters” to sell more firearms to a smaller number of people. This industry interest in opposing the government, Murphy argued, has pushed the National Rifle Association away from making any compromise.

“By sitting down and negotiating with the government about stricter gun laws, it runs counter to that narrative about the government coming to get you that prompts increasing gun sales,” he said.

Because of the central role of guns in the conservative narrative, Democrats cannot hope to change the conservative position simply by talking about the policy benefits of new laws, Murphy argued.

One strategy for Democrats is to build up the political strength of gun violence organizations to rival the strength of the NRA. Murphy said there had been progress in building up the gun violence prevention movement since Sandy Hook.

Another is for Democratic leaders to hit harder against the gun industry’s financial influence over the NRA, in hopes of “making gun owners rethink whether the NRA is really the best vehicle for them to express their views in Washington and state capitols”.

Clinton has made criticism of the firearms industry and the NRA a recurring theme of her presidential campaign. Facing criticism, Sanders has also touted his poor legislative ratings from the NRA.

In addition, Murphy said, to laughter: “We have to start thinking about ways in which Republicans can prove their anti-government bona fides other than their fealty to the NRA-gun lobby position.

“I’m not saying we’re going to pay for consultants to help them do this, but I think we have to admit that if we are probably not going to convince them on the merits, we have to give them a different outlet to talk about things like freedom and liberty, other than this question of guns.

He added later: “It might not be the best course of action to just stand our ground, pardon the pun, and argue our case. I think you have to look at the other side and help prescribe them a way to get them to a more helpful place.”

In Newtown, he said, the legacy of the 2012 shooting lingers.

“Sandy Hook today is still in crisis,” he said. At the elementary school where survivors are studying now, each classroom has a “safe word” that children can shout if another child starts talking about their memories of what happened on the day a disturbed young man shot his way into their school.

The long game for advocates of gun violence prevention, Murphy said, was to make state laws across the country reflect state laws in Connecticut, including universal background checks and a ban on assault weapons.

Murphy said that if Democrats win both the White House and the Senate in November, he expects to see the filibuster, which was responsible for the defeat of background check legislation in the Senate, either ended or “substantially amended”.